Crank shaft



Jun 24, 1930. .1.. DAM'BLANO CRANK SHAFT med umh 2,6', 192e a sheets-smi 2 Patented June 24, 193i()l *5P-Aren r Hreife/ N vLouis DAMBLANC, or minis., FRANCE CRANE SHAFT 1.

Application filed March 26, 11B-28, "Sera1.No.'264,670, and in France March 26,*1927.

15 quent cate of aviation motors where the crank. is made ot several pieces; but in a ocin-y that. bei' of cases .and chie-ily in automobile motors consideration ot' the net cost and rsimplicity o manufacture necessitate the adoption ot 2@ crank shafts of einglepiecef My invention has precisely for an object,v embodiments ot' eccentrics and their` control elements,` particularly applicable in the case'of crank Shafts of a single piece. i

According to the invention the eccentrieally disposed sleeves are buil-t up ot' several pieces joined together by Suitable means.

Preferably the toothed n'ieinbers carried either by the sleeves tlieniselvessA or 'by ringe or parte ot ringe fixed on the said sleeves; ere 'le piece. They are provided with teeth ot an appreciable depth over half their periphery which iefeuicient for the proper' centrol ot' the eccentric. 1

as l'jall-bearinge, the sleeve eccentrically dis,-

` posed furnished with restingpointe ,of sufficient diameter inorder that the bearings can he introduced by paseing them through the elbows ci the crank. f Attaching is facili# tated by liollowi C posed sleeve. Y K

The traneniiseionfroni one eccentric to the following `onoie realized by ineens of three toothed WheeleI oixsectoi'e. The first eccentric transmits its movement to a. toothed Sector situated on the othertace of the" arm of the crank by nieane oi one or several connecting pieces passing' beneath `the said arni. The

to driven eccentric receives itenioveinent from shaft on the arin for preventing the loose pl i y tactical realization of eccentrica.

rol elements aiidtheir` assembly crank pins 3 and 4. .Onthe ln orderl to allow the useo'i bearings, Snell' rsleeiee 5 and 6 (Figs. len-d'2);

" vvout the cceentrically disf a less diameter zi tooti'ied wheel keyed directly thereon or integral therewith. 'An intermediate Vpinion placed on the saine face of the aun transmits the movement .ofthe sector to the Wheel.

lt would be interesting to provide a lifted in the sector otthe connecting-.piece aetride" Ythe arm. i i

l may advantageously eliminate the'intermediate pinion and give to the sector and the wheel such diineneionethat they conic diL li'lectly intoengavgenient. y n Itis tolbe understood that' the gear traine which have been spoken ot are celled eeea tor and. Wheel tor convenience et eizplanation and that it willisufice in each case that the part furnished with teeth embrace e sector long enough to allow the desired rotation.

By way of example and for facilitating fun# deretanding ot the description', the accompanying drawing Shows an -en'ibod'inient' Otl the invention in Which: A. .y

Fig. l-ifs an elevational View partly'in section of a .crank Shaft showing the iiret `and paid; ofthe eeeondcrlanlt; 'f Y.

Fig. 2"is a section on the'lin'cV 2-2 ofV Figui; s Y n Fig. 3 is section .on they-line ,3 8 otFig. l; and j. .Y j

Fig. -1 isa section on the line .4e/Tl of l? l. The part of ,the lcran-l'cfehat repreeeiited inv Fig. `l compreee-twfo varnier l rand gan-d two y 4 nl'pins arev mounted eccentrics .consisting ,Ottwo hali- `Meirribersi7 Aand 8 are fasten ed .together vby bolts'9fand on the two parte of the eccentric' sleeve by ineens of bolts vl() parallel to the shaft'. The two parte fand .G conetituting the eccentric arelurnished Witlilanges 20 on which arejtted the ball bearings. -Tlie said bearings are providediwith ball racesvof 2f()` islarge .enougfh'thatthe bearings be puti'n place by passim-'g above theiel'bows of the ler-ank arbor. For'allowing assembly of the-Various element-s the central Apart V2l of the sleeve isV 03ET theelhows of :the crank shaft end collected at...

e single piece, for `the diameter of the'lsjuri'aceef than that ofthe langeSQO, so that after having, .passed theV bearings .above the middle of the crank pin, then slid in place are the two parts of the eccentric sleeve and then finally the ball bearings are brought to their definite position on the circular flanges 20.

I may proceed in the same way for the toothed rings or a single piece, in the case where it is possible to give them a sufficient diameter. y

The general control of the eccentrics is effected by the shaft 22 carrying a pinion 23. The pinion 23 meshes with the sector 8 keyed on the eccentric 5 or made integral therewith.

Movement is transmitted from the eccentric 5 to the eccentric 24 in the following nia-nner: i

A toothed sector 25 (Figs. 1 and 2) is provided with a shaft 11 which turns freely in a recess 12 coaxial with the crank pin 3. The sector 25 is fitted to theA eccentric 5 by a connecting piece 13 which strides the arm 2. The interior surface of the piece 13 is bored in a way to bear on a suitably rectified portion 14 (F ig. et) on the periphery of arm 2. y

The rotation of the eccentric 5, of the connecting piece 13, and of sector 25 which is rigid therewith is limited by the presence of arm 2. The connecting piece is determined in such a way as to present the desired resistance and to allow an angle of rotation suitable for the operation of the eccentric. This angle represented at 15, 16. 17 (Fig. 4) is about 100? in the embodiment illustrated.

A pinion 1S centered on a boss of arm 2 is in engagement with the sector 25. `It drives the toothed wheel 19 rigid with the eccentric 24 which is to be controlled.

It wil-l be noticed that the overall longitudinal dimensions are diminished due to the presence of gears on a single face of arm 2. This arm is not in any way `pierced from one end to the other and its resistance is therefore greater. Moreover the lubricating conduits do not meet the shaft and can be pierced directly in the arm for leading the lubricant from one crank pin to another. This arrangement likewise allows conserving of the same length'for the last crank pin as in the case of a normal crank shaft. l

It is to be understood that I may provide the gears on the other face of the arm or on,

the interior thereof without departing from the scope of theV invention except as comprehended within the claims.

by passing them over the elbows of the said crank shaft.

2. In a motor crank shaft having a plurality of eccentrics mounted on the crank pins thereof for varying the length of stroke, the combination of a connecting piece rigidly connected to one of the said eccentrics mounted on the crank pin, said connecting piece passingover the arm of the crank shaft which connects to the said crank pin, and means for transmitting the movement of said connecting piece to other of said eccentrics on the other of said crank pins.

8. In a motor crank shaft as set forth in claim 2, a toothed sector rigid with the connecting piece and turning on the face of the crank shaft arm opposite to the eccentric on which the connecting piece is fastened, the said toothed sector meshing with the control gearing of the eccentric on the other crank pin.

4. In a motor crank shaft as set forth in claim 2, a toothed sector rigid with the coniecting piece, the said toothed sector meshing with the control gearing of the eccentric on the other crank pin a pivot for said connecting piece, the said pivot being coaXially disposed with respect to the eccentric to which the connecting piece is fastened and mounted on the face of the crank shaft arm opposite the said eccentric.

5. In a motor crank shaft as set forth in claim 24a toothed sector rigid with the connecting piece and turning on the face of the 'crank shaft arm opposite to the eccentric 0n which the connecting piece is fastened, a pinion meshing with said toothed sector, said pinion being journalled on the same face of the said arm and meshing with the toothed control sector of the eccentric keyed on the following crank pin.

LOUIS DAMBLANC. 

